Phenylephrine - Substance Search

Summary TheDrug.Wiki

Phenylephrine is primarily used as a decongestant, vasopressor, and mydriatic agent. It has poor oral bioavailability (~38%) due to extensive first-pass metabolism. The FDA has questioned its efficacy as an oral decongestant, with studies showing it performs no better than placebo at standard 10 mg doses.

Dose Information TheDrug.Wiki

ROA	Light	Common	Strong	Heavy
Nasal	0.25-0.5mg	-	-	-
Ophthalmic	1-2.5%	-	-	-

Light Common Strong Heavy

Onset, Duration & After-effects TheDrug.Wiki

ROA	Onset	Comeup	Peak	Offset
Oral	15-30 min	30-60 min	1-2 hrs	1-2 hrs
Nasal	5-10 min	10-20 min	15-30 min	1-2 hrs
Ophthalmic	1-5 min	-	30-60 min	2-4 hrs

Effect Profile

4 reports

Scores (1–10) curated from multiple sources:

Effect keyword matching from PsychonautWiki catalog
Weighted by importance: core (×3), major (×2), minor (×1)

Full methodology

Stimulant 5.8

Strong 6/10

Strong anxiety/jitters with moderate euphoria, focus, and stimulation

Stimulation / Energy ×3

6

stimulation wakefulness alertness enhancement

Euphoria / Mood Lift ×2

7

euphoria cognitive euphoria motivation enhancement

Focus / Productivity ×2

7

focus enhancement motivation enhancement thought acceleration

⚠ Anxiety / Jitters ×1

10

anxiety restlessness increased heart rate vasoconstriction

Based on reports from:

Erowid Experience Reports PsychonautWiki Phenylephrine

Tolerance

Build-up develops rapidly after a single use (serotonergic psychedelic)

Reset 7–14 days for baseline

Tolerance Decay

Full tolerance 4d Half tolerance 7d Baseline ~14d

Tolerance data primarily reflect intranasal, continuous daily use leading to rhinitis medicamentosa (tachyphylaxis/rebound). Onset of clinically relevant tolerance and rebound has been reported as early as ~3 days; symptoms generally improve within days to a few weeks after cessation with supportive care. Systemic tolerance patterns are less defined. Data quality is limited and variably generalizable.